The invention relates to a support assembly for semi-trailers or the like and consists of two driven spindle-jacks each with two telescoping inner and outer tubing and each with one bevel-gear drive, one of these drives being actuated by spur-gearing itself actuated by a handcrank, the bevel-gear shaft of this bevel-gear drive penetrating the spur-gearing and forming part of the same and being supported at the opposite end as well as between its ends in the outer tubing.
It has been conventional practice so far in spindle-jacks used in such support assemblies to support the bevel-gear shaft at one end as well as between its ends in the outer square-section of a spindle-jack and to support it at its other end in the spur-gear drive-housing, and to do this by means of a plurality of sleeve bearing, e.g., three bearings. However, to prevent undue friction and accordingly low efficiency, the sleeve bearings must be carefully aligned in the assembly of the jack, whereby difficulties are encountered in mass production, as the spindle jacks in question are welded together, extruded, molded or rolled components being used in part. For instance the roller outer square-sections may not be satisfactorily right-angular in cross-section. If the sleeve bearings are improperly aligned, the bevel-gear shaft may cant, or the angularly offset seating of the bevel-gear may result in the further drawback that the bevel-gear rests by its shoulder against the inside wall of the outer square tubing and thereby moves within it only on one side, whereby there is degradation in the functioning of the spindle-jack.